Orthodontic toothbrushes of the sort herein are adapted to clean teeth and prevent decalcification and gingivitis which can result in areas around orthodontic appliances. Prior art orthodontic toothbrushes typically involve head designs with channels of shorter bristles to accommodate the brackets and brace elements while adjacent taller bristles clean the gumline (gingival surface) or top (occlusal surface) of the teeth.
One typical orthodontic toothbrush is described in U.S. Pat. No. 6,260,227 to Fulop, et al., disclosing a toothbrush head wherein the bristle pattern forms a V-shaped channel far less than the depth of a typical bracket or band. The shortest group of bristles is positioned along the center row of the longitudinal centerline axis. Adjacent to the shortest bristles is an intermediate row, bilaterally, to clean the occlusal (top) and gingival (bottom) portions of the tooth's crown and bracket and band. Adjacent to the intermediate height bristles are rows of tufts of taller bristles. A fourth set of the tallest bristles is located at the distal end of the toothbrush head. The limit of this design is that the bristle heights create a V-shaped channel longitudinally whereas the anatomy of a typical brace is square in this dimension. The bristles of the V-shaped design diverge away from the area of the brace which is most difficult to clean and where the highest degree of decalcification occurs: the area of the brace which is immediately adjacent to the tooth.
U.S. Pat. No. 5,325,560 to Pavone, et al., discloses a similar orthodontic toothbrush where the bristles also form a channel for the brace elements. The Pavone toothbrush has outermost rows of bristles of relatively soft and long length. The bristles in the pattern gradually shorten in length, with the shortest and stiffest bristles positioned along the longitudinal centerline axis. In addition, U.S. Pat. No. 4,706,322 to Nicolas, teaches another orthodontic toothbrush with a channel for brace elements. The Nicolas toothbrush has shorter bristles in the middle and two longitudinal rows of tufts of taller bristles inclined towards the outside of the brushing head and diverging from the median longitudinal plane, while two other rows of tufts are angled towards the median longitudinal plane.
When brushes with channels of the sort described, having shorter, near-uniform length of bristles, are used on teeth with brackets, the shorter bristles forming the depth of the channel tend to cause the brush to glide atop the outermost surface of the brackets. This gliding action prevents the bristles adjacent to the channel from reaching or effectively cleaning the surfaces of the underlying tooth which are farthest from the toothbrush head.